not delivering cairo on mac os x build

Hello,

i'm trying to sort out building with --enable-headless on mac os x, with 
the attached patch it does not try to build cairo and pixman anymore but 
somewhere cairo is still expected:

/Users/stage/Documents/riccardo/libo/solenv/gbuild/Library.mk:54: *** 
gb_Deliver_deliver: file does not exist in solver, and cannot be 
delivered: 
/Users/stage/Documents/riccardo/libo/solver/unxmacxi.pro/lib/libcairo.dylib. 
 Stop.

Any hint?

thanks,
riccardo

diff --git a/RepositoryExternal.mk b/RepositoryExternal.mk
index 57b7249..6f9dae1 100644
--- a/RepositoryExternal.mk
+++ b/RepositoryExternal.mk
@@ -525,6 +525,7 @@ endif # ANDROID
 
 endif # SYSTEM_REDLAND
 
+ifeq ($(GUIBASE),headless)
 
 ifeq ($(SYSTEM_CAIRO),YES)
 
@@ -581,6 +582,8 @@ endef
 
 endif # SYSTEM_CAIRO
 
+endif # headless
+
 define gb_LinkTarget__use_freetype
 $(call gb_LinkTarget_set_include,$(1),\
        $$(INCLUDE) \